JP2007186605A - Polycarbonate-based flame-retardant resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate-based flame-retardant resin composition with improved appearance characteristics (suppressing occurrence of silver marks) of a molded product on molding without detriment to its excellent flame retardancy. <P>SOLUTION: This polycarbonate-based flame-retardant resin composition comprises 45-94.5 mass% polycarbonate-based resin (a), 5-50 mass% inorganic particles (b) containing a composite of silicon dioxide and aluminum oxide, and 0.5-5 mass% higher fatty acid ester compound (c) obtained from a higher fatty acid and a phenol compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polycarbonate-based flame-retardant resin composition, a flame-retardant molding material and a molded article using the same.

  Resin compositions used in the field of electrical and electronic equipment are required to have a high degree of flame retardancy from the viewpoint of safety, and are therefore widely researched and developed as “flame retardant resins”. Among these flame retardant resins, polycarbonate resin is a material that has been actively studied because of its excellent heat resistance and electrical characteristics.

For example, Patent Document 1 includes a polycarbonate resin and particles containing a composite of silicon dioxide and aluminum oxide in order to stably obtain excellent flame retardancy, and a cumulative 50% particle size of the particles. Describes a polycarbonate-based resin composition containing inorganic particles, characterized in that is 10 μm or less. However, in the resin composition, although the appearance characteristics of the molded product at the time of molding (the occurrence of silver is small) is improved to some extent, the generation of silver cannot be sufficiently suppressed, and the appearance characteristics of the molded product are still sufficient. I can't say that.
JP-A-2005-272808

  Then, an object of this invention is to provide the polycarbonate-type flame-retardant resin composition which the external appearance characteristic at the time of shaping | molding improves (suppresses generation | occurrence | production of silver), without impairing the outstanding flame retardance.

As a result of diligent research, the present inventor has found that the above object can be achieved by adding a specific additive to a polycarbonate resin composition containing inorganic particles.
That is, the present invention relates to polycarbonate resin (a) 45 to 94.5% by mass, inorganic particles (b) 5 to 50% by mass containing a composite of silicon dioxide and aluminum oxide, higher fatty acid and phenol compound. A polycarbonate-based flame retardant resin composition (hereinafter sometimes simply referred to as “resin composition”) comprising 0.5 to 5% by mass of a higher fatty acid ester compound (c) composed of To do. In the composition, the 50% cumulative particle size of the inorganic particles (b) is preferably 10 μm or less.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition which the external appearance characteristic at the time of shaping | molding improves (suppresses silver generation) can be provided, without impairing the outstanding flame retardance of polycarbonate-type resin.

［式中、Ｒ⁴およびＲ⁵は、それぞれ炭素数１〜６のアルキル基または炭素数６〜１２のアリール基を示し、それぞれ同じであっても異なるものであってもよく、ｍおよびｎは、それぞれ０〜４の整数である。Ｚは、単結合、炭素数１〜６のアルキレン基またはアルキルデン基、炭素数５〜２０のシクロアルキレン基、シクロアルキルデン基、フルオレニリデン基、または−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−若しくは−ＣＯ−結合を示す。］ Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention.
<Polycarbonate resin>
The polycarbonate resin in the present invention is a resin containing a polycarbonate unit represented by the following general formula.

[Wherein, R ⁴ and R ⁵ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be the same or different, and m and n are , Each is an integer of 0 to 4. Z is a single bond, an alkylene group having 1 to 6 carbon atoms or an alkylden group, a cycloalkylene group having 5 to 20 carbon atoms, a cycloalkylden group, a fluorenylidene group, or -O-, -S-, -SO-, shows the or -CO- bond - -SO _2. ]

  A polycarbonate resin is a polymer obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonic ester such as diphenyl carbonate are reacted. Is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' -Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone Such as sulfones, and the like.

  These are used singly or as a mixture of two or more. However, those having no halogen substituent are preferable from the viewpoint of preventing discharge of the gas containing halogen concerned at the time of combustion into the environment. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, hydroquinone, and the like may be mixed and used.

Furthermore, the above dihydroxydiaryl compound and a trivalent or higher phenol compound as shown below may be used in combination.
Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The number average molecular weight of the polycarbonate resin is preferably 10,000 or more and 100,000 or less. When the number average molecular weight of the polycarbonate resin is 10,000 or more, a resin composition having excellent mechanical strength or flame retardancy can be stably obtained. Further, when the number average molecular weight of the polycarbonate resin is 100,000 or less, the viscosity of the resin composition falls within an appropriate range, and the moldability becomes good. In producing a polycarbonate-based resin, a molecular weight regulator, a catalyst, or the like can be used as necessary. The moisture content of the polycarbonate resin is not particularly limited, but is, for example, 1,000 ppm or less. If the moisture content is within such a range, the production stability of the resin composition is improved.

  When the total amount of the flame-retardant resin composition of the present invention is 100% by mass, the content of the polycarbonate-based resin is 45% by mass or more, more preferably 60% by mass or more. Moreover, this content is 94.5 mass% or less, Preferably it is 80 mass% or less, More preferably, it is 75 mass% or less. By setting it as such content, the outstanding flame retardance is obtained combined with the effect | action of an inorganic particle.

<Inorganic particles>
The inorganic particles used in the present invention mean particles composed mainly of inorganic components. It is not intended to exclude inorganic particles containing a small amount of organic components. The inorganic particles are particles containing a composite of silicon dioxide and aluminum oxide. This means particles comprising a silicon dioxide phase and an aluminum oxide phase. Specific examples thereof include particles containing a composite oxide of silicon dioxide and aluminum, particles in which silicon dioxide particles and aluminum oxide particles are fused, and the like. Fly ash is a suitable example of particles containing such a complex. According to the study of the present inventor, by using inorganic particles having such a structure as a flame retardant, excellent flame retardancy that cannot be obtained with silicon dioxide particles alone, aluminum oxide particles alone, or a mixture thereof is realized. can do.

  The inorganic particles preferably further include aluminum oxide particles and silicon dioxide particles in addition to the particles containing the composite. By using such inorganic particles containing a plurality of different types of particles, a flame retardant resin composition having excellent flame retardancy can be stably obtained. Examples of such inorganic particles include inorganic particles made of a mixture of silicon and aluminum composite oxide, silica particles, and alumina particles. The fly ash mentioned later can also be mentioned as an example of the inorganic particle containing such several types of particle | grains.

  Such inorganic particles that are inexpensive to obtain are not particularly limited, and examples thereof include fly ash. While the incineration ash obtained from garbage incinerators is combustion ash obtained by burning various miscellaneous things, fly ash is the coal combustion ash of a thermal power plant, so the identity of raw materials is clear The content of heavy metals other than silicon and aluminum is lower than that of the combustion ash. Also, it is relatively easy to control the content of heavy metals and the like in fly ash. Therefore, fly ash also has an advantage that it does not adversely affect the environment when added as a flame retardant to a polycarbonate resin. Further, when such inorganic particles are used, a polycarbonate resin composition having sufficient flame retardancy can be obtained even if the blending amount of a phosphorus flame retardant, a halogen flame retardant, or the like is reduced. From the viewpoint of environmental protection, it is preferable that the amount of the phosphorus-based flame retardant and the halogen-based flame retardant is 0.

  Hereinafter, the particle size of the inorganic particles will be described. The D50 (50% diameter) of the inorganic particles in the present invention is preferably 1 μm or more, more preferably 3 μm or more. The D50 is preferably 10 μm or less, more preferably 7 μm or less. When D50 is 1 μm or more, the flame retardancy of the resin composition is improved. Moreover, the fall of the moldability of a resin composition can also be suppressed. Moreover, scattering of inorganic particles is suppressed, and workability and handling stability in the manufacturing process of the resin composition are improved.

  When D50 is 3 μm or more, the flame retardancy of the resin composition is further improved. Moreover, scattering of inorganic particles is further suppressed, and workability and handling stability in the manufacturing process of the resin composition are further improved. When D50 is 10 μm or less, the flame retardancy of the resin composition is improved. Moreover, the fall of the moldability of a resin composition can also be suppressed. When D50 is 7 μm or less, carbonization of the polycarbonate-based resin is further promoted at the time of combustion, and as a result, the flame retardancy of the resin composition is further improved.

  Here, commercially available fly ash usually has a D50 particle size of more than 10 μm. For this reason, in the present invention, it is preferable to use a fly ash having such a large particle size that is not used as it is and whose particle size is controlled by classification treatment or the like. Thereby, the synergistic effect of the said polycarbonate-type resin and an inorganic particle is acquired notably, and the outstanding flame retardance can be implement | achieved stably. Moreover, the moldability of the resin composition is also maintained well. Examples of the method for controlling the particle size of the inorganic particles include a classification process using a sieve having a specific opening, a classification process using an airflow classification device, and the like.

  In addition to satisfying the above particle size conditions defined by D50, the inorganic particles in the present invention preferably satisfy the following particle size conditions defined by the volume average particle size. The volume average particle diameter of the inorganic particles is preferably 1 μm or more, more preferably 3 μm or more, preferably 10 μm or less, more preferably 7 μm or less. When the volume average particle diameter of the inorganic particles is 1 μm or more, the flame retardancy of the resin composition is improved. Moreover, the moldability of the resin composition is improved. Moreover, scattering of inorganic particles is suppressed, and workability and handling stability in the manufacturing process of the resin composition are improved.

  When the volume average particle diameter of the inorganic particles is 3 μm or more, the flame retardancy of the resin composition is further improved. Moreover, scattering of inorganic particles is further suppressed, and workability and handling stability in the manufacturing process of the resin composition are further improved. When the volume average particle diameter of the inorganic particles is 10 μm or less, the flame retardancy of the resin composition is improved. Moreover, the moldability of the resin composition is improved. When the volume average particle size of the inorganic particles is 7 μm or less, the flame retardancy of the resin composition is further improved.

  Moreover, in addition to satisfy | filling the said particle size conditions prescribed | regulated by D50 or a volume average particle diameter, it is desirable for the inorganic particle in this invention to satisfy | fill the particle size conditions prescribed | regulated as follows. That is, the inorganic particles preferably contain particles having a particle size of 20 μm or less, preferably 70% or more, more preferably 90% or more. When the ratio of particles having a particle size of 20 μm or less is 70 cumulative% (number cumulative) or more based on the whole inorganic particles, flame retardancy is improved. Moreover, the fall of the moldability of a resin composition is suppressed. In addition, when the ratio of particles having a particle size of 20 μm or less is 90 cumulative% (several cumulative) or more, the flame retardancy of the resin composition is further improved. Moreover, the fall of the moldability of a resin composition is further suppressed.

  The particle size of the inorganic particles can be measured by a method such as cross-sectional observation with an electron microscope of a molded product obtained using the resin composition. Specifically, an ultrathin section of the resin composition is observed using a transmission electron microscope, or a cut surface of the resin composition is observed using a scanning electron microscope, and a photograph is taken. Individual particle diameters are measured for 100 or more particles in the resin composition. Further, the particle diameter of each particle is determined by determining the area S of the particle, and using S, (4S / π) 0.5 is defined as the particle diameter of each particle. Or the particle diameter of this inorganic particle can also be measured by the light-scattering method mentioned later.

  In this invention, content of an inorganic particle is 5 mass% or more in the whole resin composition. The content of inorganic particles is 50% by mass or less, preferably 40% by mass or less. When the content of the inorganic particles is 5% by mass or more, the effect of improving the flame retardancy of the resin composition is stably obtained. Moreover, the fall of the moldability of a resin composition can be suppressed stably. Moreover, since the ratio of the resin component or inorganic particle in a resin composition becomes appropriate as content of an inorganic particle is 50 mass% or less, a flame retardance improves. Moreover, the molding of the resin composition is further facilitated. When the content of the inorganic particles is 40% by mass or less, the flame retardancy of the resin composition is further improved. Moreover, the moldability of the resin composition is further improved. Furthermore, when the content of the inorganic particles is 30% by mass or less, it is easy to maintain the high bending strength of the molded product, and therefore, it becomes even better.

<Fly ash>
As the inorganic particles in the present invention, fly ash described in Patent Document 1 is preferably used. Fly ash (hereinafter referred to as “FA” as appropriate) refers to finely pulverized coal ash produced in a thermal power plant or the like in which coal is burned by a pulverized coal combustion system.
Fly ash contains the following ingredients. Here, the component amounts are exemplary.
(A) Silicon dioxide: 44 mass% or more and 80 mass% or less (b) Aluminum oxide: 15 mass% or more and 40 mass% or less (c) Other components: A small amount of ferric oxide (Fe ₂ O ₃ ) or titanium oxide (TiO ₂ ), magnesium oxide (MgO), calcium oxide (CaO), and the like.

Silicon dioxide: content (silica SiO ₂₎ is preferably at 44 wt%, and more preferably at least 50 wt%. Moreover, Preferably it is 85 mass% or less, More preferably, it is 75 mass% or less. When the content of silicon dioxide is within this range, the flame retardancy improving effect of the resin composition can be stably obtained due to the synergistic action of the inorganic particles and the polycarbonate resin composition.

The content of aluminum oxide (alumina: Al ₂ O ₃ ) is preferably 10% by mass or more, more preferably 15% by mass or more. Moreover, Preferably it is 40 mass% or less, More preferably, it is 30 mass% or less. When the content of aluminum oxide is within this range, the flame retardancy improving effect of the resin composition can be stably obtained due to the synergistic action of the inorganic particles and the polycarbonate resin composition.

  Among these components, the total content of silicon dioxide and aluminum oxide is preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more. Further, the total content of silicon dioxide and aluminum oxide is preferably 99% by mass or less, and more preferably 95% by mass or less. When the total content of silicon dioxide and aluminum oxide is within this range, the flame retardancy improving effect of the resin composition can be stably obtained by the synergistic action of the inorganic particles and the polycarbonate resin composition.

Part of the silicon dioxide and aluminum oxide may form a composite oxide. Further, a part of the silicon dioxide and aluminum oxide may form a silicon dioxide phase and an aluminum oxide phase in the particles to form particles having a multiphase structure. The components such as ferric oxide (Fe ₂ O ₃ ), titanium oxide (TiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO), as long as the amount is small, There is no particular decrease in moldability. In addition to these oxides, fly ash contains trace amounts of heavy metals, but the concentration of trace amounts of heavy metals is lower than incineration ash obtained from a garbage incinerator or the like. This is because the incineration ash is combustion ash obtained by burning various miscellaneous things, whereas fly ash is coal combustion ash of a thermal power plant.

  In addition, since the raw material features are clear, it is relatively easy to control the content of heavy metals and the like in fly ash. As will be described later, by taking measures against elution of trace amounts of heavy metals, the environmental impact risk of the resin composition and its molded product can be further reduced. Fly ash is a fine particle, and when viewed with an electron microscope, most of the particles are spherical. For this reason, when fly ash is used, flame retardancy can be improved while suppressing a decrease in moldability during molding of the resin composition.

  Since fly ash is generated in large quantities in thermal power plants and the like, and most of it is industrial waste, there is an advantage that procurement costs are low. Therefore, the manufacturing cost of the resin composition having flame retardancy can also be reduced. Further, since fly ash has relatively stable quality such as particle size and composition, a resin composition having flame retardancy can be obtained stably.

  One type of fly ash, which is a representative example of inorganic particles used in the present invention, has a D50 of 3.9 μm, and most (97 cumulative% or more) of fly ash has a particle size of 20 μm or less. Moreover, the particle size of most fly ash (96 cumulative% or more) is 0.5 μm or more. Further, a characteristic distribution (bimodal distribution) having two particle size distribution peaks in the vicinity of the particle size of 1.5 μm and the particle size of about 6.0 μm is shown. Thus, when the fly ash which has two peaks of a particle size distribution is included, the flame retardance of a resin composition becomes stable and favorable. Moreover, the fall of the moldability of a resin composition is suppressed stably. In general, commercially available fly ash has a volume average particle size of 17 μm or more and a D50 particle size of 10 μm or more.

  In the present invention, the D50 particle size is controlled to 10 μm or less by classifying commercially available fly ash with a 20 μm diameter sieve. Therefore, flame retardance can be stably realized by the synergistic action of the polycarbonate resin and the inorganic particles. Moreover, the fall of the moldability of a resin composition can be suppressed stably.

  Depending on the use environment or use method of the fly ash-containing resin composition, a trace amount of heavy metal may be eluted. In the flame-retardant resin composition of the present invention, when fly ash is used as the inorganic particles, a measure against elution of a trace amount of heavy metal may be applied within a range that does not deteriorate various physical properties and appearance of the resin composition. . As a countermeasure against elution, a method of adding a predetermined elution inhibitor to the resin composition, or forming a film having an elution prevention function on the surface of a molded product of the resin composition (for example, containing a predetermined elution inhibitor) The paint can be applied.) By taking measures against elution, even if the content of heavy metals varies slightly due to the type of coal that is the raw material of fly ash and the combustion conditions during fly ash production, the elution of heavy metals is reliably suppressed. be able to. Moreover, since fly ash can be used regardless of the content of heavy metals and the like, fly ash that is a by-product of a thermal power plant can be used more effectively as a resource.

  As a countermeasure against elution of heavy metals and the like, the method of adding an elution inhibitor to the resin composition is simple and effective even for long-term use. The required amount of the elution inhibitor is effective in preventing elution of heavy metals and the like when the relative mass ratio to fly ash is 1/1000 or more, particularly preferably 1/100 or more. Examples of elution inhibitors for heavy metals include inorganic compound adsorbents and reducing agents, and ion exchange resins.

  Examples of the adsorbent and reducing agent for inorganic compounds include ferrous sulfate, ferric sulfate, Schwertmannite, sodium thiosulfate, hydrotalcite, hydroxyapatite, and particularly preferably ferrous sulfate. Is mentioned. Examples of the ion exchange resin include chelate resins, anion exchange resins, and cation exchange resins.

  The effect of these elution inhibitors is that the adsorbent forms an adsorbent such as a hydrous oxide of a metal such as iron in the resin to adsorb heavy metals, or the reducing agent reduces heavy metals. And insolubilization. Furthermore, the combined use of a reducing agent and an adsorbent may reduce heavy metals and the like, and may be more easily adsorbed. Therefore, a plurality of adsorbents and reducing agents may be mixed and used.

  However, since the dissolution inhibitor is often a water-containing drug such as a hydrate, when excessively added, the water evaporates when the resin composition is injection-molded, and silver stripes ( (Hereinafter referred to as “silver”) and discoloration due to the dissolution inhibitor may occur, resulting in a decrease in the design of the molded product. For this reason, the addition amount of the dissolution inhibitor is preferably less than 2.0% by mass at most, more preferably 1.0% by mass or less. When 10% by mass of fly ash is added to the resin composition in a mass ratio, the dissolution inhibitor is blended at 0.01% by mass or more, particularly preferably 0.1% by mass or more and less than 2.0% by mass. Thus, appearance defects such as silver can be suppressed during molding, and elution of heavy metals can be prevented.

  When forming a film having an elution preventing function on the surface of a molded article of the resin composition, a method of coating the surface of the molded article with a water repellent or moisture permeation preventive film can be used. The water-repellent film is not particularly limited, but for example, a fluororesin film can be used. When used together with the elution inhibitor, it is more effective in preventing elution of heavy metals and the like.

<Higher fatty acid ester compound>
The higher fatty acid ester compound used in the present invention is a higher fatty acid ester compound composed of a higher fatty acid and a phenol compound. In a resin composition comprising a polycarbonate resin and inorganic particles, the greater the amount of inorganic particles added, the better the flame retardancy, but the dispersibility of the inorganic particles is reduced, and the resin flow is not uniform during molding. Inferred to occur, silver is generated, resulting in poor appearance.

  The higher fatty acid ester compound composed of the higher fatty acid and the phenolic compound is improved in the fluidity of the resin composition at the time of molding because the phenolic compound part has affinity with the aromatic ring structure of the polycarbonate resin. It is inferred that the flow of water improves more uniformly, and silver generation is suppressed.

  The blending amount of the higher fatty acid ester compound in the resin composition is preferably 0.5% by mass to 5% by mass, and if it is less than 0.5% by mass, the fluidity of the resin composition at the time of molding is not sufficiently improved, and silver is generated. Cannot be sufficiently suppressed. In addition, when the blending amount exceeds 5% by mass, the higher fatty acid ester compound itself tends to burn slightly when it is molded at 280 ° C. in the examples described later, and flame retardancy can be maintained. Disappear.

  The higher fatty acid that is a component constituting the higher fatty acid ester compound is preferably a higher fatty acid having 10 to 24 carbon atoms, and examples thereof include lauric acid, myristic acid, palmitic acid, and stearic acid. When the number of carbon atoms is less than 10, the heat resistance of the higher fatty acid ester compound is lowered, and tends to decompose during molding at 280 ° C. in Examples described later. On the other hand, when the number of carbon atoms exceeds 24, the higher fatty acid ester compound becomes difficult to disperse in the polycarbonate resin, and the shape of the molded product tends to be poor.

  The higher fatty acid ester compound used in the present invention is preferably an ester compound composed of a higher fatty acid and a phenol compound, and the heating loss value in an air atmosphere at 280 ° C. is preferably 10% or less. When the heating loss value exceeds 10%, the heat resistance is lowered, and the generation of silver cannot be suppressed due to an increase in decomposition or volatile components during molding at 280 ° C. in Examples described later.

  Examples of the phenol compound which is a component constituting the higher fatty acid ester compound used in the present invention include polyoxyethylene nonylphenol, polyoxyethylene octylphenol, polyoxyethylene bisphenol A, polyoxyethylene bisphenol F, and the like. The number is preferably 1-10. Using an aliphatic compound instead of an aromatic compound improves the uneven flow of the resin during molding due to low affinity with polycarbonate resin and reduced dispersibility when inorganic particles are added. The effect is not seen.

<Fluoropolymer>
In the present invention, a fiber-forming type that forms a fiber structure (fibrillar structure) in a resin composition containing a polycarbonate-based resin, a resin composition containing a polycarbonate-based resin, the above inorganic particles, and a higher fatty acid ester compound. It is preferable to blend a fluorine-containing polymer. By blending the fiber-forming fluorine-containing polymer, it is possible to prevent the drip phenomenon during combustion.

  The fiber-forming fluorine-containing polymer is produced from polytetrafluoroethylene, a tetrafluoroethylene copolymer (for example, tetrafluoroethylene / hexafluoropropylene copolymer), a partially fluorinated polymer, or a fluorinated diphenol. And polycarbonate. The fiber-forming fluoropolymers include fine powder fluoropolymer, fluoropolymer aqueous disperse, powder fluoropolymer / acrylonitrile / styrene copolymer mixture, and also powder fluoropolymer / polymethyl methacrylate. Various forms of fluoropolymers such as mixtures can be used.

  The blending amount of the fiber-forming fluorine-containing polymer is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on the whole flame retardant resin composition. Further, it is preferably 5% by mass or less, more preferably 1% by mass or less, and further preferably 0.8% by mass or less. When the blending amount of the fluorine-containing polymer is 0.05% by mass or more, the effect of preventing dripping during combustion can be stably obtained. Moreover, the flame retardance of a resin composition becomes still more favorable that the compounding quantity of a fluorine-containing polymer is 0.1 mass% or more.

  Further, when the blending amount of the fluorine-containing polymer is 5% by mass or less, it is easy to disperse in the resin, so that it is easy to mix uniformly with the polycarbonate resin, and stable production of a flame retardant resin composition can be achieved. It becomes possible. Moreover, a flame retardance becomes much more favorable that the compounding quantity of a fluorine-containing polymer is 1 mass% or less. When the blending amount of the fluorine-containing polymer is 0.8% by mass or less, the flame retardancy of the resin composition is further improved.

  Next, the present invention will be described more specifically with reference to examples and comparative examples. The raw materials used in Examples and Comparative Examples are as follows. In the following text, “%” is mass%.

(1) Used raw materials The details of the raw materials used below are as follows.
(1-1) Caliber 301-22 (weight average molecular weight 47,000, number average molecular weight 27,000) manufactured by Sumitomo Dow Co., Ltd. was used as the polycarbonate resin (PC).
(1-2) As the inorganic particles, fly ash (FA) containing a 50% cumulative particle size of 5 μm and the constituent components containing SiO ₂ : 63.7% and Al ₂ O ₃ : 20.6% was used.
(1-3) Polytetrafluoroethylene (also abbreviated as PTFE in this specification) was used as the fiber-forming fluorine-containing polymer.

(1-4) As the higher fatty acid ester compound A-1, polyoxyethylene bisphenol A lauric acid ester composed of a higher fatty acid and an aromatic compound was used.
As the higher fatty acid ester compound A-2, a polyoxyethylene nonylphenol lauric acid ester composed of a higher fatty acid and an aromatic compound was used.
As the higher fatty acid ester compound A-3, a polyoxyethylene octylphenol lauric acid ester composed of a higher fatty acid and an aromatic compound was used.
As the higher fatty acid ester compound B-1, behenic acid monoglyceride composed of a higher fatty acid and a fatty acid compound was used.
As the higher fatty acid ester compound B-2, a montanic acid ester composed of a higher fatty acid and a fatty acid compound was used.

(2) Production of resin composition or resin molded article Polycarbonate-based resin, fly ash (FA), polytetrafluoroethylene (PTFE) and higher fatty acid ester compound are listed in Table 1 in a continuous kneading extruder having a cylinder diameter of 30 mm. The mixture was supplied by blending, melted and kneaded at 270 ° C., then cooled in water and cut into pellets. By drying the obtained resin composition at 120 ° C. for 4 hours, and then molding it at a cylinder temperature of 280 ° C. and a mold setting temperature of 80 ° C. using an injection molding machine with a clamping force of 20 tons. The flame retardant evaluation of the resin composition and the appearance characteristics (silver) were evaluated.

(3) Various evaluations (3-1) Incombustibility evaluation is performed by using a test piece (125 mm × 13 mm × 1.6 mm) for evaluation of flame retardancy obtained by injection molding at a temperature of 23 ° C. and a humidity of 50%. The sample was allowed to stand for 48 hours, and was evaluated by flame retardancy in accordance with UL94 test (flammability test of plastic materials for equipment parts) defined by Underwriters Laboratories. The UL94 test is a method for evaluating the flame retardancy from the afterflame time and drip property after indirect flame of a burner for 10 seconds on a test piece of a predetermined size held vertically. Divided into classes shown.

  In addition, when taking combustion forms other than the said classification | category, it classified as notV-2. Incidentally, if the flame retardancy is arranged in the order from good to bad, V-0, V-1, and (V-2 or notV-2) are obtained.

  The after-flame time shown above is the length of time that the test piece continues to burn with flame after the ignition source is moved away. The cotton ignition by drip is about 300 mm below the lower end of the test piece. It is determined by whether a certain marking cotton is ignited by a drip from the specimen.

(3-1) Appearance characteristics (silver) are evaluated by visually observing the surface of a molded product, and the resulting symbols correspond to the following evaluations.
○: No silver is observed, and the appearance is quite good.
X: Generation | occurrence | production of silver is observed a little and an external appearance is not so favorable.

  From the results shown in Table 1, from Examples 1 to 5 and Examples 6 and 7, higher fatty acid ester compound A-1 or A-2 or A-3 composed of higher fatty acid and phenol compound is 0.5% or more. It can be seen that the molded product of the resin composition blended with the polycarbonate-based resin at 5% or less retains excellent flame retardancy, and no appearance of silver is seen and the appearance is quite good.

  From Comparative Example 1, when molding is performed using only a polycarbonate-based resin, ignition by dripping from the test piece is observed. Therefore, from Comparative Example 2, the effect of preventing dripping during combustion can be stably obtained by blending PTFE 0.5%, which is a fluorine-containing polymer. As shown in Comparative Example 3, when 25% of fly ash is blended as inorganic particles, although the flame retardancy is excellent, generation of silver is observed in the molded product.

  From the comparative example 4, in the molded article of the resin composition in which the higher fatty acid ester compound A-1 is blended with the polycarbonate-based resin at less than 0.5%, some silver is generated and the appearance is not so good. From the comparative example 5, in the molded article of the resin composition which mix | blended higher fatty acid ester compound A-1 with the ratio over 5%, although generation | occurrence | production of silver is suppressed, a flame retardance falls remarkably.

  From Comparative Examples 6 to 13, in the higher fatty acid ester compounds B-1 and B-2 composed of higher fatty acid and an aliphatic compound, 0.5% or more having a silver suppressing effect in the higher fatty acid ester compound A-1. It can be seen that the effect of suppressing silver is not observed even when a molded article of a resin composition in which is added to a polycarbonate resin is produced.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition which the external appearance characteristic at the time of shaping | molding improves (suppresses silver generation) can be provided, without impairing the outstanding flame retardance of polycarbonate-type resin.

Claims (2)

  Higher fatty acid composed of polycarbonate resin (a) 45-94.5% by mass, inorganic particles (b) 5-50% by mass containing a composite of silicon dioxide and aluminum oxide, higher fatty acid and phenol compound A polycarbonate flame-retardant resin composition comprising 0.5 to 5% by mass of an ester compound (c).   The flame retardant resin composition according to claim 1, wherein the inorganic particles (b) have a cumulative 50% particle size of 10 μm or less.